[FoRK] Larry Masinter talk today: origins of Lisp at PARC & modern Medley

Ken Meltsner meltsner at alum.mit.edu
Tue Dec 8 12:35:48 PST 2020


Argh. (cons x y) => (x . y) — the list (x y) is (cons x (cons y nil))

On Tue, Dec 8, 2020 at 12:33 PM Ken Meltsner <meltsner at alum.mit.edu> wrote:

> You’re correct.  CDR correspond to “rest of” and CAR is “first.”  And
> since a proper list ends with NIL, rest of (1 2) is (2). And rest of that
> is () or NIL, which makes the test for the end of a list cheap.
>
> It’s clearer with box and pointer diagrams.
>
> Ken “Haven’t used Lisp seriously for > 30 years” Meltsner
>
> On Tue, Dec 8, 2020 at 10:48 AM Gregory Alan Bolcer <greg at bolcer.org>
> wrote:
>
>> Just yesterday I dusted off my lisp skills.  Wikipedia had and entry and
>> CAR and CDR which seemed wrong.    I thought:
>> (car (1 2)) = 1
>> (cdr (1 2)) = (2)
>>
>> But the wikipedia article said cdr was the atom of '2', not the list of
>> '2'.
>>
>>
>> https://www.gnu.org/software/emacs/manual/html_node/eintr/car-_0026-cdr.html
>>
>> https://en.wikipedia.org/wiki/CAR_and_CDR
>> Thus, the expression (car (cons x y)) evaluates to x, and (cdr (cons x
>> y)) evaluates to y.
>>
>> I was going to write a correction, but gave up.  I am a Lisp aficionado
>> to the core.
>>
>> Greg
>>
>> On 12/8/2020 10:30 AM, Rohit Khare wrote:
>> > Short notice, as it's today at 3PM Pacific:
>> > https://www.meetup.com/LispNYC/events/vqhmbpybcqblb/
>> >
>> > I'm looking forward to learning more, but also seeing how Larry's making
>> > the most of his post-Adobe career. I was glad to see him at the Computer
>> > History Museum last year, with the same sparkle in his eye :)
>> >
>> > Stay safe,
>> >    Rohit
>> >
>> > PS. The event link isn't resolving for me, so LMK if you make it:
>> >
>> https://meet.lisp.nyc/LarryMasinterTheMedleyInterlispProjectStatusAndPlans
>> >
>> > Medley Interlisp is the environment from the old Xerox Lisp machines,
>> which
>> >> was spun out to a company called Envos, which then turned into Venue.
>> >>
>> >
>> >
>> >> It was once a commercial software development environment aimed at the
>> >> 1980s AI market, and it contained many influential ideas. Notecards,
>> for
>> >> example, was a conceptual predecessor of Apple's Hypercard, and D-EDIT
>> and
>> >> S-EDIT are sort of the canonical ancestral structure editors.
>> Masterscope
>> >> and the "file package" included system-management tools that combined
>> >> features of version control and build systems, with comprehensive cross
>> >> referencing support.
>> >>
>> >
>> >
>> >> Medley was the latest release of the Xerox Lisp environment, before the
>> >> whole environment was renamed Medley. It was originally written in
>> >> Interlisp (a dialect separate from the MACLISP/Common Lisp tradition,
>> with
>> >> its own ancestry), but later, Common Lisp also became part of the
>> >> environment. Medley includes WYSIWYG text editor (TEdit), email
>> organizer
>> >> (Lafite), performance tools (Spy) and many other libraries and user
>> >> contributed code (from the 1980s).
>> >>
>> >
>> >
>> >> The 1992 ACM Software System Award, to Daniel G. Bobrow, Richard R.
>> >> Burton, L. Peter Deutsch, Ronald M. Kaplan, Larry Masinter, Warren
>> Teitelman
>> >>
>> >
>> >
>> >> for their pioneering work in programming environments that integrated
>> >> source-language debuggers, fully compatible integrated
>> >> interpreter/compiler, automatic change management, structure-based
>> editing,
>> >> logging facilities, interactive graphics, and analysis/profiling tools
>> in
>> >> the Interlisp system.
>> >>
>> >
>> >
>> >> At this point the base system is usable enough on 64-bit OSes and quite
>> >> fast (A $40 pi runs Lisp > 150 times faster than a $30,000 Xerox 1108
>> in
>> >> 1982).
>> >>
>> >
>> >
>> >> https://interlisp.org
>> > _______________________________________________
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>> >
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> --
> After 30+ years of email, I have used up my supply of clever .sig material.
>
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After 30+ years of email, I have used up my supply of clever .sig material.


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